In a typical packaging machine for placing groups of articles, such as bottles or cans, within individual cartons, the cartons are stacked in a collapsed form in a supply hopper at one end of the packaging machine. The collapsed cartons, otherwise known as carton blanks, are individually removed by a carton selecting mechanism or feeder, such as a rotary feeder, and placed on one or more carton carriers, such as lugs, that travel in a direction parallel to the flow of articles. With one type of packaging machine, the cartons are placed between adjacent pairs of carton carriers. The carton selecting mechanism has vacuum cup assemblies for extracting a leading carton blank in the stack and for releasing the carton after the carton has been positioned between the carton carriers. The carton blanks become opened by centrifugal force upon rotation of the vacuum assemblies away from the stack and toward the carriers, by moving the carton against static guides, or by the contact of the carton with the traveling carriers.
One or more chains or belts move the cartons in a downstream direction in synchronism with the operation of the feeder so that the cartons are placed on the one or more carriers, such as between adjacent pairs of the lugs. The cartons are supported by the carriers such that two side walls of each carton are parallel to the length of the carriers, the front and rear walls are parallel to the direction of article flow, and the two bottom panels respectively depend from the front and rear walls. As the cartons are moved in the downstream direction, a cam mechanism bends the bottom panels away from each other up to an approximate angle of ninety degrees relative to the front and rear walls of the carton.
It should be understood that the naming of the various walls or panels of a carton vary with the size, shape, and style of the carton. In the above-identified carton, the walls and panels of a carton are defined such that, when the carton is in an assembled state holding articles, the front and rear walls of the carton are vertically oriented and extend along the length of the article group, the side walls are vertically oriented and extend along the width of the article group, and the bottom panels are horizontally oriented and extend underneath the article group.
After the bottom panels have been placed in a horizontal orientation by the cam mechanism, a second set of carriers forces the cartons along a set of rails down onto the articles. The second set of carriers typically has at least one lug for engaging a top portion of the carton so that the carton may be pulled from the top and one or more additional lugs for protruding through cut-outs in both of the bottom panels so that the carton may be pulled from the bottom. The walls of the carton remain in a generally vertical orientation as the carton is pulled along the rails by the second set of carriers.
The second set of carriers lowers the carton onto an article group and releases the carton at which time the bottom panels drop down to a vertical orientation. As the carton is travelling downstream with the article group, a second cam mechanism bends the bottom panels of the carton up underneath the articles and the bottom panels are fastened to each other, such as by glue or interlocking members on the bottom panels.
The above-described packaging machine has several disadvantages and/or limitations. For instance, the typical packaging machine is limited to cartons which are `four crease` cartons. A `four crease` carton only has four vertical creases or bends with each bend being located at one of the four corners of the carton. When a `four crease` carton is flattened into a carton blank, the front wall and one side wall form one planar portion and the rear wall and other side wall form a second planar portion parallel to and connected to the first planar portion. Also, with a carton blank, the bottom walls depend down from the front and rear walls and are offset relative to each other. The packaging machine is limited to `four crease` cartons since the cartons are opened by centrifugal force or by contacting the cartons with static guides or with the lugs. Other cartons, such as a `six crease` carton which has additional vertical bends down the center of the two side walls, might not fully open upon rotation of the carton from the supply hopper to the traveling carriers. Because the packaging machine is limited to `four crease` cartons, the packaging machine is rather restricted in the types of cartons that can be used in packaging articles. For instance, the above-described packaging machine would be unable to place articles within any type of carton which is formed from a carton blank having front and rear walls are opposite each other, such as with clips, wraps, tamper evident cartons, or neck-through cartons. It is therefore a desire in the industry to be able to package articles into a wider variety of carton types.
The placement of the carton blanks in the supply hopper presents another difficulty with the typical packaging machine. The carton blanks are generally planar and are typically positioned within the supply hopper with one of the bottom panels resting on the bottom of the supply hopper. Since the bottom panels are typically of unequal length, the weight of the front and rear walls and the two side walls is resting entirely upon only one of the two bottom panels. The bottom panels, however, are rather weak structurally and can easily collapse or become damaged due to the weight of the carton blank while supplied into the feeder by a magazine. A damaged or collapsed carton interrupts and impedes the packaging process.
The typical packaging machine is unable to operate at relatively high speeds since the packaging machine can operate only as fast as the feeder can select and open the carton blanks. For the packaging machines that open cartons by centrifugal force, the feeder is limited by the action of the centrifugal force or by the static guides or lugs. For instance, if the feeder is rotated at too high of a speed, the centrifugal force generated by the rotation of the vacuum assemblies would quickly open the cartons and would also close the cartons before they reach the carriers. Since the cartons would be at least partially closed upon reaching the traveling carriers, the carriers would be unable to receive the carton from the vacuum assembly. The packaging machine is therefore unable to operate at fairly high speeds.
The typical packaging machine is unable to positively open the cartons. The opening methods by which a typical packaging machine operates do not ensure that the carton will open and, instead, frequently cause a carton to misfeed due to the carton being folded inwardly or to the carton collapsing. The effectiveness of these opening methods depends in part on certain carton characteristics, such as the stiffness, rigidity, age, and crease strength of the carton. Thus, for many cartons, one or more of these characteristics would prevent the packaging machine from being able to package articles into these cartons. The reliability of these opening methods also depends partially upon the quality of the cartons. A carton with a low quality, such as one which has glue spattered between the walls or has incomplete cuts, would not open with these opening methods. Thus, a need exists for a packaging machine which can positively open cartons.
As another disadvantage, the traveling cartons, articles, and related machinery are fairly difficult to access. As stated above, the cartons are moved in the downstream direction by two sets of traveling carriers. The first set of traveling carriers receives the cartons from the carton feeder and contacts the two side walls of each carton while the second set of traveling carriers engages the bottom panels on either side of each carton as well as the top portion of each carton. The two sets of carriers, as well as the chains and other elements for moving the carriers, are positioned on either side and above the cartons and thus limit the amount of access to the cartons, articles, and related machinery. The cartons also encounter two different cam mechanisms while traveling in the downstream direction. Each of these cam mechanisms complicates the packaging machine and also further restricts the amount of access to the cartons. This limited amount of access to the cartons and bottles is highly detrimental to the operation of the packaging machine. For instance, when operation of the packaging machine is interrupted because of a carton jam or an article jam, the limited amount of access to the cartons, articles, carriers, and related elements may complicate a clean out operation and can significantly increase the amount of down time. The limited amount of access to the related machinery also complicates and increases the time needed to perform necessary maintenance or to perform repairs.
Thus, a need therefore exists in the industry for a packaging machine that can package articles of various sizes into a wider variety of carton types and sizes and one that positively opens the cartons. A need also exists for a packaging machine in which the cartons, articles, and related machinery are more easily accessed. Further, a need exists for a packaging machine which stacks carton blanks in a manner that improves the control of the cartons into the feeder. Moreover, a need exists for a packaging machine which can operate at higher speeds.